1. Field of the Invention
The present invention relates to a data collecting and processing device having a keyboard, and more particularly to an improvement in such device by the provision of housing means having a first case and a second case mutually connected in a foldable manner for movement between open and folded, or closed, positions.
2. Description of the Prior Art
Conventional portable devices of this type are generally provided with a plurality of key switches arranged in a plane, as input means, with the number of switches increasing if a large number of different types of information must be inputted, such as in functional calculators. Therefore, the data collecting device requires a large number of keys. As a result, such devices require a large area for the keyboard, and become excessively large for carrying, and thereby losing a most important advantage of devices of this type.
In order to solve the above problem, one method is to reduce the size of each key, thereby to allow the number of keys to be increased for a given keyboard area. This approach has the shortcoming that the keys become so small that they are difficult to depress and may require the use of an implement, such as a pen, as the case may be, for operating the keys. A second method is to give at least some of the keys a plurality of functions. This approach has the shortcoming that it makes operation of the device undesirably complicated.
In order to circumvent such drawbacks, a foldable structure composed of a keyboard unit is known. Kishimoto. et al., U.S. Pat. No. 4,395,704, describes a foldable structure composed of a display unit and a keyboard unit which are foldably connected to be opened for use and closed for carrying.
However, portable data collecting devices designed for uses such as for taking a patron's food or drink order in a restaurant by a waiter, require more keys than do calculators. In this case, the problems described above continue to exist.